Condoms or a vasectomy are basically the only contraceptive options currently available for men. But a new gene discovery by infertility researchers at the Centre for Reproductive Health at the University of Edinburgh suggests that the development of a male contraceptive pill could someday be possible.

While studying infertility in mice, the researchers identified a gene called Katnal1 that appears to be critical during the late stages of sperm production. In the testes, Katnal1 regulates a protein needed by cells that support sperm maturation; without it, sperm do not develop properly and the body disposes of them.

In lab studies, the research team found that mice with genetic mutations that interrupted Katnal1 became infertile.

Although the research is still in the preliminary stages, the authors say that if a drug could be developed to hinder Katnal1, it could potentially serve as a reversible contraceptive.

“If we can find a way to target this gene in the testes, we could potentially develop a non-hormonal contraceptive,” researcher Dr. Lee Smith of the University of Edinburgh said in a news release. “The important thing is that the effects of such a drug would be reversible because Katnal1 only affects sperm cells in the later stages of development, so it would not hinder the early stages of sperm production and the overall ability to produce sperm.”

As Dr. Allan Pacey, a senior lecturer in andrology at the University of Sheffield, told BBC News:

The key in developing a non-hormonal contraceptive for men is that the molecular target needs to be very specific for either sperm or other cells in the testicle which are involved in sperm production.

If they are not, then such a contraceptive could have unwanted side effects on other cells and tissues in the body and may even be dangerous.

Researchers have long sought new forms of male contraception. In January, researchers from the University of North Carolina School of Medicine found that ultrasound waves could be used to zap sperm into oblivion. In their rat study, exposure to high-frequency ultrasound for two 15-minute sessions, two days apart, was enough to kill existing sperm in the testes and stop the development of additional sperm.

“Although other research is being carried out into non-hormonal male contraceptives, identification of a gene that controls sperm production in the way Katnal1 does is a unique and significant step forward in our understanding of testis biology,” Smith said.

In the future, the Scottish team hopes to test their findings on humans — if they can guarantee its effect is reversible.